Magnetic tape recording apparatus

ABSTRACT

The invention relates to a magnetic tape recording apparatus which can record digital image data sufficient to allow a good image to be displayed upon variable speed reproduction in the long time mode. When image data for variable speed reproduction (for example, sixteenfold speed reproduction) is recorded discretely at positions which are traced by a rotary head upon variable speed reproduction, in the long time mode, the number of recording times of image data for same variable speed reproduction is increased and the number of sync blocks recorded in one recording operation is decreased when compared with those in recording in the standard mode. For example, in the standard mode, six sync blocks are recorded three times, but in the long time mode, four sync blocks are recorded four times. The present invention can be applied to a recording and reproduction apparatus which displays a good image upon variable speed reproduction.

TECHNICAL FIELD

This invention relates to a magnetic tape recording apparatus, and moreparticularly to a magnetic tape recording apparatus wherein, where areproduction is performed at a variable speed in a long time mode forfeeding a tape at a speed lower than that in a standard mode, data canbe acquired with certainty and a good image can be displayed.

BACKGROUND ART

In recent years, a technique for compressing and recording image dataand sound data has been advanced and practically applied. For example,the MPEG (Moving Picture Expert Group) method is used as a compressionmethod of a high efficiency.

The applicant of the present application has formerly proposed areproducing method in Japanese Patent Laid-open No. 2001-36412. Forexample, the method reproduces the recorded image data, at a variablespeed including a twofold speed or more in the forward direction and anon-magnified speed or more in the reverse direction, from a recordingmedium in which image data interframe-compressed by a high efficiencycoding method such as the MPEG2 are recorded by a helical scanningmethod, in the case that the track width of a magnetic head forrecording and the width of a track to be recorded are equal to eachother.

In the proposal, data for variable speed reproduction is discretelyrecorded at positions which are to be traced upon variable speedreproduction, and also the arrangement pattern wherein the data isrecorded matches with the interleave. Consequently, data can be acquiredwith certainty upon variable speed reproduction, and matching betweentwo kinds of regularity of image data for variable speed reproductionand the interleave can be established upon editing such as intermittentsuccessive recording.

The above-mentioned proposal, however, has such problems as describedbelow. In particular, if a magnetic tape is fed at a low speed whencompared with a speed in a standard mode as in, for example, a long timemode to record data, then the crosstalk amount from a same azimuth trackneighboring across one track increases and the number of sync blockswhich can be acquired by one trace decreases, when compared withcrosstalk amount and a number of sync blocks where a magnetic tape onwhich data is recorded in a standard mode is reproduced at a highvariable speed. There is the possibility that a failure in acquisitionof the data may occur, accordingly.

Further, the influence of a bend of a recording track arising from arecording apparatus or a reproduction apparatus, distortion of a traceupon reproduction, a displacement of the position of a recording trackby jitters of velocity servo upon recording, a deviation of the feedingspeed by jitters of position lock servo upon reproduction and so forthincreases as the recording track width decreases with respect to thetrack width of the recording magnetic head. As a result, with a magnetictape of a long time mode, an error of a trace with respect to a targetposition upon high speed reproduction occurs more significantly thanwith a magnetic tape of a standard mode, and there still is a subjectthat a failure in acquisition of the data may occur.

DISCLOSURE OF INVENTION

The present invention has been made taking such a situation as describedabove into consideration, and the object of the present invention isthat, upon variable speed reproduction in a long time mode, data can beacquired with certainty and a good image can be displayed, when data forvariable speed reproduction is recorded discretely at positions whichshould be traced upon variable speed reproduction. And, the object isaccomplished by decreasing the number of sync blocks to be recorded inone area in one track with respect to the number of sync blocks whichcan be acquired by one trace per one track and by increasing the numberof areas in each track, as the recording track width decreases withrespect to the track width of a recording magnetic head.

A first magnetic tape recording apparatus of the present invention ischaracterized by comprising inputting means for inputting digital imagedata, extraction means for extracting digital image data for variablespeed reproduction from the digital image data inputted by the inputtingmeans, production means for producing, from the digital image dataextracted by the extraction means, digital image recording data forvariable speed reproduction to be recorded into a predetermined area ofa first region positioned substantially at the center of the track orpredetermined areas of both of the first region and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track, andrecording means for recording the digital image recording data forvariable speed reproduction produced by the production means into thefirst and second regions such that the number of unit blocks in one areawhen the digital image recording data for variable speed reproduction isrecorded in the long time mode is smaller than the number of unit blockswhen the digital image recording data for variable speed reproduction isrecorded in the standard mode.

A first magnetic tape recording method of the present invention ischaracterized by comprising an inputting step of inputting the digitalimage data, an extraction step of extracting digital image data forvariable speed reproduction from the digital image data inputted by theprocess at the inputting step, a production step of producing, from thedigital image data extracted by the process at the extraction step,digital image recording data for variable speed reproduction to berecorded into a predetermined area of a first region positionedsubstantially at the center of the track or predetermined areas of bothof the first region and a second region positioned at a position whichis traced upon variable speed reproduction in a track positioned in theneighborhood of the track, and a recording step of recording the digitalimage recording data for variable speed reproduction produced by theprocess at the production step into the first and second regions suchthat the number of unit blocks in one area when the digital imagerecording data for variable speed reproduction is recorded in the longtime mode is smaller than the number of unit blocks in one area when thedigital image recording data for variable speed reproduction is recordedin the standard mode.

A first recording medium of the present invention is characterized inthat a program comprises an inputting control step of controllinginputting of digital image data, an extraction step of extractingdigital image data for variable speed reproduction from the digitalimage data whose inputting is controlled by the process at the inputtingcontrol step, a production step of producing, from the digital imagedata extracted by the process at the extraction step, digital imagerecording data for variable speed reproduction to be recorded into apredetermined area of a first region positioned substantially at thecenter of the track or predetermined areas of both of the first regionand a second region positioned at a position which is traced uponvariable speed reproduction in a track positioned in the neighborhood ofthe track, and a recording step of recording the digital image recordingdata for variable speed reproduction produced by the process at theproduction step into the first and second regions such that the numberof unit blocks in one area when the digital image recording data forvariable speed reproduction is recorded in the long time mode is smallerthan the number of unit blocks in one area when the digital imagerecording data for variable speed reproduction is recorded in thestandard mode.

A first program of the present invention is characterized by comprisingan inputting control step of controlling inputting of digital imagedata, an extraction step of extracting digital image data for variablespeed reproduction from the digital image data whose inputting iscontrolled by the process at the inputting control step, a productionstep of producing, from the digital image data extracted by the processat the extraction step, digital image recording data for variable speedreproduction to be recorded into a predetermined area of a first regionpositioned substantially at the center of the track or predeterminedareas of both of the first region and a second region positioned at aposition which is traced upon variable speed reproduction in a trackpositioned in the neighborhood of the track, and a recording step ofrecording the digital image recording data for variable speedreproduction produced by the process at the production step into thefirst and second regions such that the number of unit blocks in one areawhen the digital image recording data for variable speed reproduction isrecorded in the long time mode is smaller than the number of unit blocksin one area when the digital image recording data for variable speedreproduction is recorded in the standard mode.

A first magnetic tape of the present invention is characterized in thatdigital image recording data for variable speed reproduction is recordedin a predetermined area of a first region positioned substantially atthe center of a track or predetermined areas of both of the first regionand a second region positioned at a position which is traced uponvariable speed reproduction in a track positioned in the neighborhood ofthe track such that the number of unit blocks in one area when thedigital image recording data for variable speed reproduction is recordedin the long time mode is smaller than the number of unit blocks in onearea when the digital image recording data for variable speedreproduction is recorded in the standard mode.

A second magnetic tape recording apparatus of the present invention ischaracterized by comprising inputting means for inputting digital imagedata, extraction means for extracting digital image data for variablespeed reproduction from the digital image data inputted by the inputtingmeans, production means for producing, from the digital image dataextracted by the extraction means, digital image recording data forvariable speed reproduction to be recorded into a predetermined area ofa first region positioned substantially at the center of the track orpredetermined areas of both of the first region and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track, andrecording means for recording the digital image recording data forvariable speed reproduction produced by the production means into theareas of the first and second regions such that the number of areas inthe tracks when the digital image recording data for variable speedreproduction is recorded in the long time mode is greater than thenumber of areas in the tracks when the digital image recording data forvariable speed reproduction is recorded in the standard mode.

A second magnetic tape recording method of the present invention ischaracterized by comprising an inputting step of inputting digital imagedata, an extraction step of extracting digital image data for variablespeed reproduction from the digital image data inputted by the processat the inputting step, a production step of producing, from the digitalimage data extracted by the process at the extraction step, digitalimage recording data for variable speed reproduction to be recorded intoa predetermined area of a first region positioned substantially at thecenter of the track or predetermined areas of both of the first regionand a second region positioned at a position which is traced uponvariable speed reproduction in a track positioned in the neighborhood ofthe track, and a recording step of recording the digital image recordingdata for variable speed reproduction produced by the process at theproduction step into the areas of the first and second regions such thatthe number of areas in the tracks when the digital image recording datafor variable speed reproduction is recorded in the long time mode isgreater than the number of areas in the tracks when the digital imagerecording data for variable speed reproduction is recorded in thestandard mode.

A second recording medium of the present invention is characterized inthat a program comprises an inputting control step of controllinginputting of digital image data, an extraction step of extractingdigital image data for variable speed reproduction from the digitalimage data whose inputting is controlled by the process at the inputtingcontrol step, a production step of producing, from the digital imagedata extracted by the process at the extraction step, digital imagerecording data for variable speed reproduction to be recorded into apredetermined area of a first region positioned substantially at thecenter of the track or predetermined areas of both of the first regionand a second region positioned at a position which is traced uponvariable speed reproduction in a track positioned in the neighborhood ofthe track, and a recording step of recording the digital image recordingdata for variable speed reproduction produced by the process at theproduction step into the areas of the first and second regions such thatthe number of areas in the tracks when the digital image recording datafor variable speed reproduction is recorded in the long time mode isgreater than the number of areas in the tracks when the digital imagerecording data for variable speed reproduction is recorded in thestandard mode.

A second program of the present invention is characterized by comprisingan inputting control step of controlling inputting of digital imagedata, an extraction step of extracting digital image data for variablespeed reproduction from the digital image data whose inputting iscontrolled by the process at the inputting control step, a productionstep of producing, from the digital image data extracted by the processat the extraction step, digital image recording data for variable speedreproduction to be recorded into a predetermined area of a first regionpositioned substantially at the center of the track or predeterminedareas of both of the first region and a second region positioned at aposition which is traced upon variable speed reproduction in a trackpositioned in the neighborhood of the track, and a recording step ofrecording the digital image recording data for variable speedreproduction produced by the process at the production step into theareas of the first and second regions such that the number of areas inthe tracks when the digital image recording data for variable speedreproduction is recorded in the long time mode is greater than thenumber of areas in the tracks when the digital image recording data forvariable speed reproduction is recorded in the standard mode.

A second magnetic tape of the present invention is characterized in thatdigital image recording data for variable speed reproduction is recordedin a predetermined area of a first region positioned substantially atthe center of a track or predetermined areas of both of the first regionand a second region positioned at a position which is traced uponvariable speed reproduction in a track positioned in the neighborhood ofthe track such that the number of areas in the tracks when the digitalimage recording data for variable speed reproduction is recorded in thelong time mode is greater than the number of areas in the tracks whenthe digital image recording data for variable speed reproduction isrecorded in the standard mode.

The digital image data recorded in the first region may be digital imagedata which is reproduced commonly in variable speed reproduction in theforward direction and variable speed reproduction in the reversedirection.

The recording means may determine a predetermined number of tracks asone period and record the digital image data into the first and secondregions in accordance with a predetermined pattern for each period.

The recording means may record the digital image data onto a magnetictape by means of the rotary head which has an azimuth discriminated tohave a direction of recording magnetization close to the direction ofarrangement of a magnetic material of the magnetic tape.

The recording means may record, when the digital image data is to berecorded onto tracks having the opposite azimuths to each other, digitalimage data for a higher multiplied speed onto one of the tracks whichhas an azimuth of a direction of a recording magnetic field nearer tothe direction of arrangement of the magnetic material of the magnetictape and record digital image data for a lower multiplied speed onto theother track.

The recording means may produce digital image data for an n multipliedspeed and arrange and record the digital image data at n or 2n trackintervals and substantially at the center of each of the tracks, n beingan exponentiation of 2. And, the arranged digital image data is used forvariable speed reproduction in the forward direction and the reversedirection at an m multiplied speed which is an exponentiation of 2 andfor non-multiplied speed reproduction in the reverse direction.

The values n and m may be set so as to satisfy a relationship of m<n.

The recording means may record the digital image data, which is to berecorded in the first and second regions respectively, a plural numberof times in each of the first and second regions.

In the first magnetic tape recording apparatus, magnetic tape recordingmethod, recording medium, program and magnetic tape of the presentinvention, digital image data is recorded into a predetermined area of afirst region positioned substantially at the center of the track orpredetermined areas of both of the first region and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track suchthat the number of unit blocks in one area when the digital image datafor variable speed reproduction is recorded in the long time mode issmaller than the number of unit blocks in one area when the digitalimage data for variable speed reproduction is recorded in the standardmode.

In the second magnetic tape recording apparatus, magnetic tape recordingmethod, recording medium, program and magnetic tape of the presentinvention, digital image data is recorded into a predetermined area of afirst region positioned substantially at the center of the track orpredetermined areas of both of the first region and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track suchthat the number of areas in the tracks is greater than that when thedigital image data for variable speed reproduction is recorded in thestandard mode.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a configuration of an embodiment of arecording and reproduction apparatus to which the present invention isapplied;

FIG. 2 is a view illustrating compression;

FIG. 3 is a view showing a rotary head;

FIG. 4 is a view illustrating a recording pattern;

FIG. 5 is a view illustrating a relationship between an envelope of anRF signal and reproduction data;

FIG. 6 is a flow chart illustrating a production process of image datafor variable speed reproduction;

FIG. 7 is a view showing an example of a data arrangement pattern ofdata for sixteenfold speed reproduction;

FIG. 8 is a view showing another example of a data arrangement patternof data for fourfold speed reproduction;

FIG. 9 is a view illustrating details of the data arrangement patternshown in FIG. 8;

FIG. 10 is a view illustrating details of the data arrangement patternshown in FIG. 8;

FIG. 11 is a view showing a further example of the data arrangementpattern of data for sixteenfold speed reproduction;

FIG. 12 is a view illustrating details of the data arrangement patternshown in FIG. 11;

FIG. 13 is a view illustrating details of the data arrangement patternshown in FIG. 11;

FIG. 14 is a view illustrating details of the data arrangement patternshown in FIG. 11;

FIG. 15 is a view illustrating an error correction code;

FIG. 16 is a view showing an example of data arrangement patterns ofdata for fourfold speed and eightfold speed reproduction in a standardmode;

FIG. 17 is a view showing a further example of a data arrangementpattern of data for sixteenfold speed reproduction in the standard mode;

FIG. 18 is a view showing an example of a data arrangement pattern ofdata for twenty-fourfold speed reproduction in the standard mode;

FIG. 19 is a view showing an example of a data arrangement pattern ofdata for thirty-twofold speed reproduction in the standard mode;

FIG. 20 is a view showing an example of a data arrangement patterntaking the interleave in the standard mode into consideration;

FIG. 21 is a view illustrating a relationship between an envelope of anRF signal and reproduction data when the track is narrow;

FIG. 22 is a view illustrating a relationship between a track pitch anda track position displacement;

FIG. 23 is a view illustrating a relationship between the track widthsof a recording magnetic head and a magnetic tape and the envelope of theRF signal;

FIG. 24 is a view showing an example of a data arrangement pattern ofdata for fourfold speed and eightfold speed reproduction in a long timemode;

FIG. 25 is a view showing an example of a data arrangement pattern ofdata for sixteenfold speed reproduction in the long time mode;

FIG. 26 is a view showing an example of a data arrangement pattern ofdata for twenty-fourfold speed reproduction in the long time mode;

FIG. 27 is a view showing an example of a data arrangement pattern ofdata for thirty-twofold speed reproduction in the long time mode;

FIG. 28 is a view showing an example of a data arrangement pattern withthe interleave in the long time mode taken into consideration; and

FIG. 29 is a view illustrating media.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, an embodiment of the present invention is describedwith reference to the drawings. FIG. 1 is a view showing a configurationof an embodiment of a recording and reproduction apparatus to which thepresent invention is applied. An image signal outputted from a videocamera or the like (not shown) is inputted to an A/D (Analog/Digital)conversion section 2 of a recording and reproduction apparatus 1. Theanalog image signal inputted to the A/D conversion section 2 isconverted into digital image data and outputted to a compressionprocessing section 3. The compression processing section 3 performs acompression process for the inputted image data in accordance with apredetermined method and outputs the resulting data to a datamultiplexing section 4 and a variable speed reproduction data productionsection 5.

Where the MPEG method is used for the compression process to beperformed by the compression processing section 3, the compressionprocessing section 3 performs DCT (Discrete Cosine Transform) conversionfor the inputted image data and performs a coding process in accordancewith the MPEG2 method for it, and outputs the compressed image data tothe data multiplexing section 4. The coding process by the MPEG2 methodis further described with reference to FIG. 2. In an image signal, forexample, fifteen frames are determined as a GOP (Group of Picture) as aunit of the compression process, and each frame of the image signal isconverted into one of three pictures called I picture, B picture and Ppicture.

The I picture is image data produced by intraframe compression. The Ppicture is image data produced not only by intraframe compression butalso by compression using information of a preceding frame. The Bpicture is image data produced not only by intraframe compression butalso by compression using information of preceding and succeedingframes.

A data stream formed from I pictures, P pictures and B pictures producedin this manner and arranged in such an order as shown, for example, at alower stage of FIG. 2 is inputted to the data multiplexing section 4 andmultiplexed with some other data (for example, sound data, system datasuch as sub codes and so forth), and then outputted to an errorcorrection code addition section 6. Also image data for variable speedreproduction produced by the variable speed reproduction data productionsection 5 is included in the data to be multiplexed by the datamultiplexing section 4.

The variable speed reproduction data production section 5 produces imagedata for only variable speed reproduction using only an I picture fromwithin the image data outputted from the compression processing section3. Details of the process just described are hereinafter described withreference to a flow chart of FIG. 6. While, as described above, the Ipicture is compressed using only intraframe data, P pictures and Bpictures are compressed using not only intraframe data but alsoinformation of other frames (pictures). This signifies that the Ppictures and B pictures can be decoded only when information of suchother pictures is read out. Since an I picture can be decoded withoutdepending upon a readout situation of any other picture, the I pictureis suitable as data to be read out in such a situation that only part ofimage data can be read out like upon variable speed reproduction.

An error correction code is further added to the multiplexed datainputted to the error correction code addition section 6, and theresulting data is supplied to a rotary head 8 through an amplifier 7-1.The rotary head 8 records the supplied data onto a magnetic tape as arecording medium not shown.

On the other hand, data including image data recorded on a recordingmedium is reproduced by the rotary head 8 and is supplied to an errorcorrection section 9 through an amplifier 7-2. The error correctionsection 9 performs an error correction process for the supplied data andoutputs resulting data to a data demultiplexing processing section 10and a variable speed reproduction memory 11. The data demultiplexingprocessing section 10 performs a process opposite to that of the datamultiplexing section 4. In particular, the data demultiplexingprocessing section 10 demultiplexes the inputted multiplexed data intodata such as image data, sound data and system data.

The image data from within the demultiplexed data is outputted to adecompression processing section 13 through a switch 12. The switch 12connected to the decompression processing section 13 is connected, uponnormal reproduction (forward direction non-magnified speedreproduction), to the terminal “a” side so that the image data from thedata demultiplexing processing section 10 can be supplied to thedecompression processing section 13, but is connected, upon any otherreproduction (variable speed reproduction), to the terminal “b” side sothat data stored in the variable speed reproduction memory 11 can besupplied to the decompression processing section 13.

Image data for variable speed reproduction produced by the variablespeed reproduction data production section 5 is stored into the variablespeed reproduction memory 11. Since, upon variable speed reproduction,data is intermittently inputted to the error correction section 9, onlyerror correction for an inner code is performed, and image data whereinerror correction is performed only for the inner code is temporarilystored into the variable speed reproduction memory 11. As a readoutmethod of the image data from the variable speed reproduction memory 11,a method wherein it is performed in a fixed cycle synchronized withframes of a reproduction image and another method wherein it isperformed when image data for one frame is stored is available, andeither one of the methods may be used.

The decompression processing section 13 performs a decompression process(process such as decoding, inverse DCT conversion and so forth by theMPEG method) for the image data inputted through the switch 12 andoutputs the resulting data to a television receiver (not shown) or thelike as a displaying device through a D/A conversion section 14.

The recording and reproduction apparatus 1 including the rotary head 8having such a configuration as shown in FIG. 3 is examined here. Therotary head 8 shown in FIG. 3 includes two heads having azimuth anglesdifferent from each other. One of the heads is specified as “+ (plus)”head, and the other head is specified as “− (minus)” head. A recordingpattern on a magnetic tape as a recording medium to be recorded by sucha rotary head as described above is formed as shown in FIG. 4. Inparticular, tracks are formed alternately by the “−” and “+” heads suchthat a track 0 is formed by the “−” head, a track 1 is formed by the “+”head, and further a track 2 is formed by the “−” head.

For example, where ninefold speed reproduction is performed, the “−”head traces nine tracks (in the example of FIG. 4, tracks 0 to 8) by onetrace so that data of a predetermined portion is read out from the ninetracks. The upper stage of FIG. 5 shows envelopes of an RF signal whenninefold speed reproduction is performed while the lower stage of FIG. 5illustrates reproduction data to be demodulated when, for example, datawhose output level ranges from a peak level to a level lower by 6 dBthan the peak level are demodulated. As shown at the lower stage of FIG.5, it can be seen that reproduction data upon variable speedreproduction makes an intermittent data string.

Thus, if the running speed of the tape as a recording medium and thephase of the head trace with respect to the tape pattern are kept fixed,then data arranged at the central position of the tape can be tracedwith certainty.

However, since increase of the speed magnification number decreases themagnitude of one lump envelopes of an RF signal described hereinabovewith reference to FIG. 5, the amount of data included in the lumpdecreases.

Accordingly, if the speed magnification number becomes large, then asufficient amount of data cannot be recorded only with the data disposedat the center. Thus, in the present invention, where the speedmagnification number is great, one piece of data is recorded discretelyin a plurality of regions. The process in this instance is describedwith reference to a flow chart of FIG. 6.

The process of the flow chart of FIG. 6 is executed by the variablespeed reproduction data production section 5 of the recording andreproduction apparatus 1 of FIG. 1. First at step S1, the variable speedreproduction data production section 5 extracts only an I picture fromcompressed image data supplied from the compression processing section3. Then at step S2, the variable speed reproduction data productionsection 5 discriminates whether or not the recording mode is thestandard mode.

If the recording mode is the standard mode, then the variable speedreproduction data production section 5 discriminates the speedmagnification number n at step S3. If n>4, that is, if the speedmagnification number n is great, then the variable speed reproductiondata production section 5 produces digital image data for first regionrecording and digital image data for second region recording(hereinafter described with reference to FIG. 7) at step S4. On theother hand, if the speed magnification number n is not n>4, for example,if the speed magnification number n is for fourfold speed reproduction,then the variable speed reproduction data production section 5 producesonly digital image data for first region recording at step S5.

Further, if it is discriminated at step S2 that the recording mode isnot the standard mode (that is, the recording mode is the long timemode), then the variable speed reproduction data production section 5discriminates the speed magnification number n at step S6. If n>4, thatis, if the speed magnification number n is great, then the variablespeed reproduction data production section 5 produces digital image datafor first region recording and digital image data for second regionrecording at step S7. On the other hand, if the speed magnificationnumber n is not n>4, that is, if the speed magnification number n is forfourfold speed reproduction, then the variable speed reproduction dataproduction section 5 produces only digital image data for first regionrecording at step S8.

FIG. 7 illustrates an arrangement of image data for variable speedreproduction at the sixteenfold speed (such data is hereinafter referredto also simply as data for sixteenfold speed reproduction) by theprocess at step S4, that is, when the speed magnification number n inthe standard mode is 16. In the present example, since n>4, when the “+”head traces a magnetic tape at the “+” sixteenfold or “−” sixteenfoldspeed, a first region is formed on a track T3 on which the “+” headpasses the center of the magnetic tape in the widthwise direction anddigital image data D3 for first region recording is disposed into thefirst region.

A second region is formed at a position, which is passed by the “+”head, of each of a track T1 (a track neighboring with the track T3across a track T2) and a track T5 (a track neighboring with the track T3across a track T4) of the same azimuth (in the example of FIG. 7, a “+”azimuth) on the opposite sides of the track T3 neighboring therewithacross one track, and digital image data D11, D12 and D51, D52 forsecond region recording are arranged in the second regions.

It is to be noted that the digital image data D3 for first regionrecording arranged in the first region of the track T3 is data forcommon use for the “+” sixteenfold speed and the “−” sixteenfold speed.In contrast, the digital image data D11 and D51 for second regionrecording are data for the “+” sixteenfold speed, and the digital imagedata D12 and D52 for second region recording are data for the “−”sixteenfold speed.

It is to be noted that, as image data for variable speed reproduction(image data for variable speed reproduction produced by the process atstep S5) upon magnified speed reproduction at a speed equal to or lowerthan the fourfold speed (for example, upon fourfold speed reproductionillustrated in FIG. 8), only the digital image data D3 for first regionrecording is recorded, but the digital image data D11, D12 and D51, D52for second region recording are not recorded.

However, such a case may possibly occur that, from such factors as abend of a recording track arising from the recording and reproductionapparatus 1, distortion of the trace upon reproduction, positiondisplacement of a recording track by jitters of velocity servo uponrecording, a deviation of the running speed by jitters of phase lockedservo upon reproduction and so forth, an error of the trace with respectto the position of a target trace occurs, resulting in failure toacquire data for variable speed reproduction provided in such a dataarrangement as described above.

In the present invention, in order to prevent this, same data forvariable speed reproduction of each track to be traced by one trace isrecorded repetitively by a plural number of times in the proximity of areference position (position traced when such an error of a trace as iscaused by such factors as described above does not occur).

As shown in FIG. 8, as to data for fourfold speed reproduction, samedata is repetitively recorded twice as data D101 and D102.

Generally, when recording onto a track on a recording medium such as amagnetic tape is performed by a trace of a rotary head, data is recordedin a unit of a sync block.

FIG. 9 is a view showing, in an enlarged scale, a data arrangement wheredata for fourfold speed reproduction is recorded twice repetitively. Inthe figure, SB denotes an abbreviation of a sync block. In the presentexample, sync blocks S0 to S15 are repetitively recorded twice as dataD101 and D102 in the longitudinal direction such that they are centeredat the center of the track. Where data is not repetitively recordedtwice, or in other words, where data is recorded only once in a centralregion of the track, the range permitted as an error in a trace is ±7SBs (sync blocks).

Upon fourfold speed reproduction, data of 30 SBs can be acquired fromone track. However, in the example of FIG. 9, data which must beacquired by one trace is data of 16 sync blocks from S0 to S15.Accordingly, where the data is repetitively recorded twice asillustrated in FIG. 9, the range permitted as an error of a traceincreases to ±15 SBs.

The number of times by which same data is recorded repetitively is notlimited to twice as described above but may be any number of times.Further, the number of times need not be an integral number of times. Anexample of a data arrangement where the number of times of repetition isset to 1.5 times is shown in FIG. 10. That same data is recordedrepetitively by 1.5 times signifies that one half of the data isrecorded once and the other half of the data is repetitively recordedtwice. In other words, in the example shown in FIG. 10, the sync blocksS0 to S7 are repetitively recorded twice and the sync blocks S8 to S15are recorded only once.

Where same data is repetitively recorded by 1.5 times, the errortolerance of a trace is ±11 SBs. Also in this instance, the tolerance ofan error of a trace is expanded when compared with the tolerance of anerror of a trace where data is recorded only once.

FIG. 11 illustrates a data arrangement where the image data D11, D12,D3, D51 and D52 shown in FIG. 7 are recorded repetitively by a pluralnumber of times in the respective tracks. The data arrangement forsixteenfold speed reproduction shown in FIG. 11 is further describedwith reference to FIGS. 12 to 14. FIG. 12 is a view illustrating detailsof the data D3 in the region which is positioned on the track T3 and inwhich same data (sync blocks S0 to S5) is repetitively recorded twice(the region in which common use data is recorded) from within the dataarrangement illustrated in FIG. 11. While the common use data isrepetitively recorded twice, the two pieces of data are spaced by adistance corresponding to 2 SBs. Further, while a necessary amount ofdata is assured by one trace, the number of times of repetition issuppressed to twice so that the amount of data for variable speedreproduction is decreased, and this contributes to increase of therecording capacity of main data (usually for non-magnified speedreproduction). This arises from the fact that it is necessary only totake into consideration the minimum error arising from servo jitters orthe like because the central region is a target position of phase lockedservo.

FIG. 13 illustrates the data D11 positioned on the track T1 in FIG. 11(or the data D51 positioned on the track T5) from within the data for“+” sixteenfold speed reproduction. The data for “+” sixteenfold speedreproduction is repetitively recorded three times. Each piece of data isformed from 3 SBs of the sync blocks S0 to S2, and the individual datais spaced from each other by a distance corresponding to 7 SBs. Whilethe number of sync blocks which can be acquired by one trace is 10,where such arrangement as described above is used, the tolerance of theerror of a trace increases to ±13.5 SBs.

Similarly, FIG. 14 illustrates the data D12 positioned on the track T1in FIG. 11 (or the data D52 positioned on the track T5) from within thedata for “−” sixteenfold speed reproduction. The data for “−”sixteenfold speed reproduction is repetitively recorded three times.Each piece of the data is formed from 3 SBs of the sync blocks S0 to S2,and the individual data is spaced from each other by a distancecorresponding to 5 SBs. While the number of sync blocks which can beacquired by one trace is 8, where such arrangement as described above isused, the tolerance of the error of a trace increases to ±10.5 SBs.

In the data arrangement shown in FIG. 13 or 14, the number of times ofrepetition is set to three and the data distance is increased to arather great distance of 7 SBs or 5 SBs so that the tolerance againstthe error in a trace can be increased.

Subsequently, error correction is described. As can be recognized fromthe configuration of the recording and reproduction apparatus 1 of FIG.1, data such as image data and sound data is multiplexed by the datamultiplexing section 4 and then error correction codes are added toresulting data by the error correction code addition section 6. Aconfiguration of the error correction codes to be added is illustratedin FIG. 15. As seen in FIG. 15, one sync block is formed from a datapart and an inner code part (Inner Parity), and an outer code part(Outer Parity) is added to one data part composed of a plurality of syncblocks. Where such a configuration as just described is taken, a highresisting property against an error in a unit of a sync block can beprovided.

Generally, it is known that, where a tape-type medium is used as arecording medium, in addition to random errors (errors which appearnon-periodically and in a single-shot manner), burst errors (errorswhich appear successively) are generated from defects of, damages to andso forth of a magnetic material applied to the tape. As a countermeasureagainst such burst errors, a single error correction outer code isprovided for sync blocks to be recorded on a plurality of tracks, andthe sync blocks are re-arranged (interleaved) over all of the tracks onwhich the sync blocks which form the code exist in accordance with apredetermined rule.

When high efficiency compression recoding is performed, if a recordingsignal process is performed in a unit of the interleave, then such aprocess as editing is facilitated and the scale of the recording andreproduction apparatus 1 can be reduced. Consequently, it is preferablethat also a recording pattern of data for variable reproduction conformsto the interleave.

Subsequently, the image data production process for variable speedreproduction (the process at steps S4 and S5 of FIG. 6) in the standardmode is described.

FIGS. 16 to 19 illustrate data arrangements for variable speedreproduction in the standard mode, and FIG. 16 illustrates a dataarrangement for fourfold speed and eightfold speed reproduction; FIG. 17illustrates a data arrangement for sixteenfold speed reproduction; FIG.18 illustrates a data arrangement for twenty-fourfold speedreproduction; and FIG. 19 illustrates a data arrangement forthirty-twofold speed reproduction.

Two pieces of data present on each of tracks T1, T17 and T33 of FIG. 16are digital image data for first region recording from within the datafor the “±” fourfold speed. Each of the two pieces of data is the samedata composed of 17 SBs and repetitively recorded twice with a gap of 10SBs left therebetween in order to increase the trace error tolerancewith respect to a region which can be acquired by a reproductionmagnetic head.

Meanwhile, three pieces of data present on each of tracks T9 and T25 ofFIG. 16 are digital image data for first region recording from withinthe data for the “±” eightfold speeds (for common use with the data forthe “±” fourfold speeds). Each of the three pieces of data is the samedata composed of 17 SBs and repetitively recorded three times without agap left therebetween.

Further, two pieces of data present on each of tracks T11 and T27 ofFIG. 16 are digital image data for second region recording from withinthe data only for the “+” eightfold speed. Each of the two pieces ofdata is the same data composed of 17 SBs and repetitively recorded twicewithout a gap left therebetween.

Furthermore, two pieces of data present on each of the tracks T7 and T23of FIG. 16 are digital image data for second region recording fromwithin the data only for the “−” eightfold speed. Each of the two piecesof data is the same data composed of 17 SBs and repetitively recordedtwice without a gap left therebetween.

Three pieces of data present on the track T3 of FIG. 17 are digitalimage data for first region recording from within the data for the “±”sixteenfold speeds. Each of the three pieces of data is the same datacomposed of 6 SBs and repetitively recorded three times with a gap of 2SBs left therebetween in order to increase the trace error tolerancewith respect to a region which can be acquired by the reproductionmagnetic head.

Meanwhile, three pieces of data only for the “+” sixteenfold speedpresent on each of the tracks T1 and T5 of FIG. 17 are digital imagedata for second region recording. Each of the three pieces of data isthe same data composed of 3 SBs and repetitively recorded three timeswith a gap of 6 SBs left therebetween in order to increase the traceerror tolerance with respect to a region which can be acquired by thereproduction magnetic head.

Three pieces of data only for the “−” sixteenfold speed present on eachof the tracks T1 and T5 of FIG. 17 are digital image data for secondregion recording. Each of the three pieces of data is the same datacomposed of 3 SBs and repetitively recorded three times with a gap of 5SBs left therebetween in order to increase the trace error tolerancewith respect to a region which can be acquired by the reproductionmagnetic head.

Three pieces of data present on the track T3 of FIG. 18 are digitalimage data for first region recording from within the data for the “±”twenty-fourfold speed. Each of the three pieces of data is the same datacomposed of 4 SBs and repetitively recorded three times with a gap of 1SB left therebetween in order to increase the trace error tolerance withrespect to a region which can be acquired by the reproduction magnetichead.

Meanwhile, four pieces of data only for the “+” twenty-fourfold speedpresent on each of the tracks T1 and T5 of FIG. 18 are digital imagedata for second region recording. Each of the four pieces of data is thesame data composed of 4 SBs and repetitively recorded four times with agap of 2 SBs left therebetween in order to increase the trace errortolerance with respect to a region which can be acquired by thereproduction magnetic head.

Four pieces of data only for the “−” twenty-fourfold speed present oneach of the tracks T1 and T5 of FIG. 18 are digital image data forsecond region recording. Each of the four pieces of data is the samedata composed of 4 SBs and repetitively recorded four times with a gapof 1 SB left therebetween in order to increase the trace error tolerancewith respect to a region which can be acquired by the reproductionmagnetic head.

Four pieces of data present on the track T5 of FIG. 19 are digital imagedata for first region recording from within the data for the “±”thirty-twofold speed. Each of the four pieces of data is the same datacomposed of 3 SBs and repetitively recorded four times with a gap of 1SB left therebetween in order to increase the trace error tolerance withrespect to a region which can be acquired by the reproduction magnetichead.

Four pieces of data only for the “+” thirty-twofold speed present oneach of the tracks T1 and T9 of FIG. 19 are digital image data forsecond region recording. Each of the four pieces of data is the samedata composed of 2 SBs and repetitively recorded four times with a gapof 2 SBs left therebetween in order to increase the trace errortolerance with respect to a region which can be acquired by thereproduction magnetic head.

Four pieces of data for only the “−” thirty-twofold speed present oneach of the tracks T1 and T9 of FIG. 19 are digital image data forsecond region recording. Each of the four pieces of data is the samedata composed of 2 SBs and repetitively recorded four times with a gapof 2 SBs left therebetween in order to increase the trace errortolerance with respect to a region which can be acquired by thereproduction magnetic head.

Four pieces of data only for the “+” thirty-twofold speed present oneach of the tracks T3 and T7 of FIG. 19 are digital image data forsecond region recording. Each of the four pieces of data is the samedata composed of 3 SBs and repetitively recorded four times with a gapof 1 SB left therebetween in order to increase the trace error tolerancewith respect to a region which can be acquired by the reproductionmagnetic head.

Four pieces of data only for the “−” thirty-twofold speed present oneach of the tracks T3 and T7 of FIG. 19 are digital image data forsecond region recording. Each of the four pieces of data is the samedata composed of 3 SBs and repetitively recorded four times with a gapof 1 SB left therebetween in order to increase the trace error tolerancewith respect to a region which can be acquired by the reproductionmagnetic head.

FIG. 20 illustrates a data arrangement for variable speed reproductionin the standard mode where the data arrangements of FIGS. 16 to 19 arecollectively represented on a single drawing and besides the interleaveis taken into consideration.

While the data arrangement patterns of FIGS. 16 to 20 described aboveare patterns where the standard mode (wherein the width of thereproduction magnetic head and the width of a recording track aresubstantially equal to each other) is supposed, if the tape runningspeed is decreased when compared with that in the standard mode, like inthe long time mode, the range over which a track recorded once isoverwritten by a next trace expands. As a result, the recording trackwidth becomes smaller than the width of the recording magnetic head (andhence the width of the reproduction magnetic head corresponding to therecording magnetic head). If the width of the recording track becomessmaller than the width of the reproduction magnetic head, then since thecrosstalk amount from neighboring tracks of the same azimuth uponreproduction increases, the overlap between RF envelopes becomes wideras shown at the upper stage of FIG. 21. Since this crosstalk originatesfrom a track having the same azimuth, the range of data of the originaltrack decreases as seen at the lower stage of FIG. 21, which disturbsdetection of the data.

In such an instance as just described, the amount of data which can beacquired per one track by one trace, that is, the number of sync blockswhich can be acquired, depends upon the crosstalk amount rather than thelevel of the main signal (reproduction signal from the original track).

If the width of the track becomes smaller than the width of thereproduction magnetic head in this manner (if the width of thereproduction magnetic head becomes great relative to the width of thetrack), then since number of sync blocks which can be acquired by onetrace decreases when compared with that in the standard mode (where thewidth of the reproduction magnetic head and the width of the track areequal to each other), there is the possibility that a failure may occurin acquisition of data from such data arrangement patterns for thestandard mode as shown in FIGS. 16 to 20.

FIG. 22 illustrates a relationship between the track pitch and the trackposition displacement. Here, where φ is the angle defined by thelongitudinal direction of the magnetic tape and the scanning directionof the rotary head 8 and Ls is the track position displacement, theposition displacement amount ΔL converted in the track direction isrepresented by the expression ofΔL=Ls tan φ  (1)

Further, where Tw is the track width, Lr is the track length convertedin proportion to the angle of 180 degrees, and n is a speedmagnification number, a relational expression oftan φ=Lr/{Tw(n±1)}  (2)is satisfied. As can be apparently seen from the expressions (1) and(2), the value of the position displacement amount ΔL converted in thetrack direction increases as the track width Tw decreases.

Accordingly, the trace error amount when the recording position of atrack is displaced by such a factor as jitters upon recording has ahigher value as the recording track width decreases if the width of therecording magnetic head is fixed, and therefore, with such dataarrangement patterns for the standard mode as shown in FIGS. 16 to 20,failure in acquisition of data sometimes occurs.

FIG. 23 represents a relationship of the RF envelope to the width of themagnetic head (rotary head 8) and the width of the recording track.Where φ is the angle defined by the longitudinal direction of themagnetic tape and the scanning direction of the magnetic head, Ltr thetrack length, Twt the recording track width, n the speed magnificationnumber, and Lp the RF envelope distance, the following expressions aresatisfied:tan φ=Ltr/{Twt(n±1)}  (3)Lp=2Twt tan φ  (4)

Further, where the width of the top of the RF envelope is represented byLt, the head width by Twh, the width of the bottom of the RF envelope byLb, the RF envelope width at the level lower by 6 dB than the peak levelby Lh, and the width of a region in which data can be acquired whencrosstalk is present by Lm, the following expressions are satisfied:Lt=(Twh−Twt)tan φ  (5)Lb=(Twh+Twt)tan φ  (6)Lh=Twh tan φ  (7)Lm=2Lp−Lb  (8)

While the number of sync blocks which are recorded in one area in onetrack (one of n areas formed when overwriting is performed n times) isdetermined from the number of sync blocks which can be acquired per onetrack by one trace, where the crosstalk amount from a track neighboringacross one track and having the same azimuth cannot be ignored as seenin FIG. 21, the level at which crosstalk begins to be picked up isdetermined as a boundary and the inner side with respect to the boundaryis determined as the width Lm of the data acquisition possible region asenlargedly shown in FIG. 23, for example.

It is to be noted, however, that the main signal can be detectedactually if a narrower one of the range of the level higher than acertain fixed level (the RF envelope width Lh of the level lower by 6 dBthan the peak level in FIG. 23) and the range in which no crosstalk ispresent (the data acquisition possible region width Lm where crosstalkis present in FIG. 23) is used as the data acquisition possible region.

From the expressions for determining the RF envelope width Lh at thelevel lower by 6 dB than the peak level and the data acquisitionpossible region width Lm where crosstalk is present as given by theexpressions (7) and (8), it can be seen that Lh<Lm is satisfied when therelationship between the recording track width Twt and the head widthTwh is Twt>(⅔)Twh. Therefore, in the present invention, when therecording track width is greater than ⅔ times the track width of therecording magnetic head, the range of the inner side of Lh (higher than−6 dB from the peak level) is determined as the data acquisitionpossible region, but when the recording track width is equal to orsmaller than ⅔ times the track width of the recording magnetic head, therange on the inner side of Lm (range within which no crosstalk ispresent) is determined as the data acquisition possible region.

Once a data acquisition possible region is determined, the number ofsync blocks which can be acquired per one track by one trace isdetermined, and consequently, also the number of sync blocks to berecorded in one area in one track is determined. In short, since thedata acquisition possible region is narrowed with the crosstalk amounttaken into consideration, the number of sync blocks which can beacquired per one track by one trace decreases. Consequently, it ispossible to detect the main signal by reducing the number of sync blockswhich are recorded in one area in one track.

Further, from the expressions (1) and (2), the position displacementamount ΔL converted in the track direction in accordance with the trackwidth Tw, that is, the trace error amount (displacement amount from thetrace target) is determined. Here, since the number of times ofrepetition of same data to be recorded in one area in a track dependsupon the trace error amount in one trace, in order to allow detection ofthe main signal, the number of times of repetition should be increasedas the position displacement amount ΔL converted in the track directionincreases.

Data arrangements of FIGS. 24 to 27 represent patterns suitable for thelong time mode with the foregoing taken into consideration for thepatterns suitable for the standard mode shown in FIGS. 16 to 19.Further, FIG. 28 shows a data arrangement where the data arrangements ofFIGS. 24 to 27 are collected in a single drawing and the interleave istaken into consideration.

FIG. 24 is a view wherein arrangement patterns for “±” fourfold speedreproduction and for “±” eightfold speed reproduction are shown on thesame drawing. As the data for the “±” fourfold speeds, data of 11 SBs isrepetitively recorded three times only in the first region with a gapcorresponding to 12 SBs left therebetween. Meanwhile, as the data for“±” eightfold speed reproduction, data of 12 SBs is repetitivelyrecorded five times in the first region without a gap left therebetween,and data of 11 SBs is repetitively recorded three times in the secondregion with a gap corresponding to 1 SB left therebetween. In thepattern of the present case, when compared with the pattern suitable forthe standard mode of FIG. 16, the number of sync blocks is smaller andthe number of times of repetition is greater (this similarly appliesalso to FIGS. 25 to 28 as can be seen apparently from the comparisonwith FIGS. 17 to 20).

FIG. 25 is a view showing an arrangement pattern of data for “±”sixteenfold speed reproduction. As the data for “±” sixteenfold speedreproduction, data of 4 SBs is recorded four times in the first regionwith a gap corresponding to 2 SBs left therebetween and data of 2 SBs isrecorded repetitively four times with a gap corresponding to 5 SBs lefttherebetween for the “+” sixteenfold speed and with a gap correspondingto 4 SBs left therebetween for the “−” sixteenfold speed.

FIG. 26 is a view showing an arrangement pattern of data for “±”twenty-fourfold speed reproduction. As the data for “±” twenty-fourfoldspeed reproduction, data of 4 SBs is repetitively recorded five times inthe first region and data of 4 SBs is repetitively recorded five timesin the second region both with no gap left therebetween.

FIG. 27 is a view showing an arrangement pattern of data for “±”thirty-twofold speed reproduction. As the data for “±” thirty-twofoldspeed reproduction, data of 2 SBs is repetitively recorded seven timeswith no gap left therebetween in the first region, but in the secondregion, data of 2 SBs is repetitively recorded eight times, or data of 1SB is repetitively recorded eight times with a gap corresponding to 1 SBleft therebetween.

FIG. 28 is a view wherein the arrangement patterns of data for “±”fourfold speed reproduction, “±” eightfold speed reproduction, “±”sixteenfold speed reproduction, “±” twenty-fourfold speed reproductionand “±” thirty-twofold speed reproduction shown in FIGS. 24 to 27 areshown on a single drawing. Further, the arrangement pattern shown inFIG. 28 is an arrangement pattern wherein the ECC interleave unit istaken into consideration. The regions for fourfold speed reproductionand the regions for eightfold speed reproduction are arranged at theshown positions in such a distance relationship that each of them isarranged at a place in each one ECC interleave unit. The regions foreightfold speed reproduction include also areas for fourfold speedreproduction and for common use.

The regions for sixteenfold speed reproduction are individually arrangedat the shown positions in such a distance relationship that one of themis arranged at once place in two ECC interleave units; the regions fortwenty-fourfold speed reproduction are individually arranged at theshown positions in such a distance relationship that one of them isarranged at one place in three ECC interleave units; and regions forthirty-twofold speed reproduction are individually arranged at the shownpositions in such a distance relationship that one of them is arrangedat one place in four ECC interleave units.

By reducing the number of sync blocks to be recorded in one area in onetrack and increasing the number of times of repetition of same data torecord the data, a good variable speed reproduction output which doesnot exhibit a missing portion in image data can be obtained not onlyupon variable speed reproduction in a tape recorded where the recordingtrack width is equal to the track width of the magnetic head as in thestandard mode but also upon variable speed reproduction in another taperecorded where the recording track width is smaller than the track widthof the magnetic head as in the long time mode. Further, a resistingproperty against deterioration of the quality similar to that in thestandard mode where the quality deterioration is caused by a dispersionamong different machines or a variation in environment can be achieved.

While the series of processes described above can be executed byhardware, it may otherwise be executed by software. Where the series ofprocesses is executed by software, a program which constructs thesoftware is installed from a recording medium into a computerincorporated in hardware for exclusive use or, for example, a personalcomputer for universal use which can execute various functions byinstalling various programs.

FIG. 29 is a view showing an example of an internal configuration of apersonal computer for universal use. A CPU (Central Processing Unit) 101of the personal computer executes various processes in accordance with aprogram stored in a ROM (Read Only Memory) 102. In a RAM (Random AccessMemory) 103, data, programs and so forth necessary for the CPU 101 toexecute various processes are stored suitably. An inputting section 106composed of a keyboard, a mouse and so forth is connected to aninput/output interface 105, and the input/output interface 105 outputs asignal inputted to the inputting section 106 to the CPU 101. Also anoutputting section 107 composed of a display unit and a speaker or thelike is connected to the input/output interface 105.

Further, a storage section 108 formed from a hard disk or the like, anda communication section 109 which performs transmission/reception ofdata to and from another apparatus through a network such as theInternet are connected to the input/output interface 105. A drive 110 isused to read out data from or write data into a recording medium such asa magnetic disk 121, an optical disk 122, a magneto-optical disk 123,and a semiconductor memory 124.

The recording medium is formed as a package medium such as, as shown inFIG. 29, a magnetic disk 121 (including a floppy disk), an optical disk122 (including a CD-ROM (Compact Disc-Read Only Memory) and a DVD(Digital Versatile Disk)), or a magneto-optical disk 123 (including anMD (MiniDisc)), or a semiconductor memory 124 which has the programrecorded thereon or therein and is distributed in order to provide theprogram to a user separately from an apparatus body. Else, the recordingmedium is formed as a ROM 102 having the program stored therein, a harddisk included in the storage section 108, or the like which are providedto a user in a state wherein they are incorporated in the computer inadvance.

It is to be noted that, in the present specification, the steps whichdescribe the program provided through a medium may be but need notnecessarily be processed in a time series in the order as described, andinclude processes which are executed in parallel or individually withoutbeing processed in a time series.

INDUSTRIAL APPLICABILITY

According to the present invention, digital image data sufficient toallow a good image to be displayed upon variable speed reproduction in along time mode can be recorded.

1. A magnetic tape recording apparatus for recording compressed digitalimage data onto a track of a magnetic tape by means of a rotary head,comprising: inputting means for inputting the digital image data;extraction means for extracting digital image data for variable speedreproduction from the digital image data inputted by said inputtingmeans; production means for producing, from the digital image dataextracted by the extraction means, digital image recording data forvariable speed reproduction to be recorded into predetermined areas of afirst region positioned substantially at the center of the track and asecond region positioned at a position which is traced upon variablespeed reproduction in a track positioned in the neighborhood of thetrack; and recording means for recording the digital image recordingdata for variable speed reproduction produced by said production meansinto the first and second regions, wherein said first region comprisesthree pieces of digital image data recorded at eightfold speed, each ofsaid three pieces of digital image data being data composed of 17 SBsand repetitively recorded three times without a gap left therebetween,wherein said second region comprises two pieces of digital image datarecorded at eightfold speed, each of said two pieces of digital imagedata being data composed of 17 SBs and repetitively recorded twicewithout a gap left therebetween.
 2. A magnetic tape recording method ofrecording compressed digital image data onto a track of a magnetic tapeby means of a rotary head, comprising: an inputting step of inputtingthe digital image data; an extraction step of extracting digital imagedata for variable speed reproduction from the digital image datainputted by the process at the inputting step; a production step ofproducing, from the digital image data extracted by the extraction step,digital image recording data for variable speed reproduction to berecorded into predetermined areas of a first region positionedsubstantially at the center of the track and a second region positionedat a position which is traced upon variable speed reproduction in atrack positioned in the neighborhood of the track; and a recording stepof recording the digital image recording data for variable speedreproduction produced by the process at the production step into thefirst and second regions, wherein said first region comprises threepieces of digital image data recorded at eightfold speed, each of saidthree pieces of digital image data being data composed of 17 SBs andrepetitively recorded three times without a gap left therebetween,wherein said second region comprises two pieces of digital image datarecorded at eightfold speed, each of said two pieces of digital imagedata being data composed of 17 SBs and repetitively recorded twicewithout a gap left therebetween.
 3. A computer-readable medium on whicha computer-readable program for a magnetic tape recording apparatus forrecording compressed digital image data onto a track of a magnetic tapeby means of a rotary head is recorded, the program comprises: aninputting control step of controlling inputting of the digital imagedata; an extraction step of extracting digital image data for variablespeed reproduction from the digital image data whose inputting iscontrolled by the process at the inputting control step; a productionstep of producing, from the digital image data extracted by theextraction step, digital image recording data for variable speedreproduction to be recorded into predetermined areas of a first regionpositioned substantially at the center of the track and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track; anda recording step of recording the digital image recording data forvariable speed reproduction produced by the process at the productionstep into the first and second regions, wherein said first regioncomprises three pieces of digital image data recorded at eightfoldspeed, each of said three pieces of digital image data being datacomposed of 17 SBs and repetitively recorded three times without a gapleft therebetween, wherein said second region comprises two pieces ofdigital image data recorded at eightfold speed, each of said two piecesof digital image data being data composed of 17 SBs and repetitivelyrecorded twice without a gap left therebetween.
 4. A magnetic taperecording apparatus for recording compressed digital image data onto atrack of a magnetic tape by means of a rotary head, comprising:inputting means for inputting the digital image data; extraction meansfor extracting digital image data for variable speed reproduction fromthe digital image data inputted by said inputting means; productionmeans for producing, from the digital image data extracted by theextraction means, digital image recording data for variable speedreproduction to be recorded into predetermined areas of a first regionpositioned substantially at the center of the track and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track; andrecording means for recording the digital image recording data forvariable speed reproduction produced by said production means into theareas of the first and second regions, wherein said first regioncomprises three pieces of digital image data recorded at eightfoldspeed, each of said three pieces of digital image data being datacomposed of 17 SBs and repetitively recorded three times without a gapleft therebetween, wherein said second region comprises two pieces ofdigital image data recorded at eightfold speed, each of said two piecesof digital image data being data composed of 17 SBs and repetitivelyrecorded twice without a gap left therebetween.
 5. A magnetic taperecording method of recording compressed digital image data onto a trackof a magnetic tape by means of a rotary head, comprising: an inputtingstep of inputting the digital image data; an extraction step ofextracting digital image data for variable speed reproduction from thedigital image data inputted by the process at the inputting step; aproduction step of producing, from the digital image data extracted bythe extraction step, digital image recording data for variable speedreproduction to be recorded into a predetermined area of a first regionpositioned substantially at the center of the track and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track; anda recording step of recording the digital image recording data forvariable speed reproduction produced by the process at the productionstep into the areas of the first and second regions, wherein said firstregion comprises three pieces of digital image data recorded ateightfold speed, each of said three pieces of digital image data beingdata composed of 17 SBs and repetitively recorded three times without agap left therebetween, wherein said second region comprises two piecesof digital image data recorded at eightfold speed, each of said twopieces of digital image data being data composed of 17 SBs andrepetitively recorded twice without a gap left therebetween.
 6. Acomputer-readable medium on which a computer-readable program for amagnetic tape recording apparatus for recording compressed digital imagedata in a standard mode or a long time mode onto a track of a magnetictape by means of a rotary head is recorded, the program comprises: aninputting control step of controlling inputting of the digital imagedata; an extraction step of extracting digital image data for variablespeed reproduction from the digital image data whose inputting iscontrolled by the process at the inputting control step; a productionstep of producing, from the digital image data extracted by theextraction step, digital image recording data for variable speedreproduction to be recorded into predetermined areas of a first regionpositioned substantially at the center of the track and a second regionpositioned at a position which is traced upon variable speedreproduction in a track positioned in the neighborhood of the track; anda recording step of recording the digital image recording data forvariable speed reproduction produced by the process at the productionstep into the areas of the first and second regions, wherein said firstregion comprises three pieces of digital image data recorded ateightfold speed, each of said three pieces of digital image data beingdata composed of 17 SBs and repetitively recorded three times without agap left therebetween, wherein said second region comprises two piecesof digital image data recorded at eightfold speed, each of said twopieces of digital image data being data composed of 17 SBs andrepetitively recorded twice without a gap left therebetween.